For the manufacturing of semiconductor devices (e.g. corresponding, integrated (analog or digital) computing circuits, semiconductor memory devices such as functional memory devices (PLAs, PALs, etc.) and table memory devices (e.g. ROMs or RAMs, in particular SRAMs and DRAMs)), so-called wafers (i.e. thin discs of monocrystalline silicon) are used.
The wafers are processed appropriately (e.g. subject to a plurality of coating, exposure, etching, diffusion and implantation process steps, etc.), and subsequently e.g. sawn apart (or e.g. scratched and broken), so that the individual devices are then available.
After the sawing apart of the wafer, the devices—which are then available individually—are loaded each individually into special housings or packages, respectively (e.g. corresponding housings adapted to be mounted by plugging or on the surface, e.g. so-called TSOP housings, etc.), and subsequently corresponding semiconductor device contacts (pads) (that are provided, for instance, at the top of the semiconductor devices) are—e.g. by means of appropriate bonding wires—connected with appropriate connection pins of the respective housing.
The connection pins serve to connect one or a plurality of semiconductor devices to a corresponding semiconductor device module (e.g. a corresponding circuit board).
The connection pins may—in particular in the case of TSOP housings—for instance extend from corresponding housing side walls (for instance from a left and a right housing side wall) laterally downwards (wherein a plurality, e.g. more than five or seven, connection pins may be arranged side by side at one and the same side wall).
When corresponding (bottom) end sections of the connection pins are soldered to corresponding pads at the circuit board, an electrical contact is produced between the corresponding module or circuit board pad, respectively, and the corresponding connection pin (and thus also an electrical contact to the corresponding semiconductor device contact (pad) connected therewith).
However, the circuit board and the semiconductor device housing connected thereto in the above-described manner in general each have different thermal coefficient of expansion.
During the heating or cooling down of a semiconductor device module, mechanical tensions will thus occur between the circuit board and the semiconductor device housing.
These mechanical tensions may be so great that a breaking up or tearing apart of the soldering connection between a connection pin and the corresponding module or circuit board pad may result.
As a rule, in the case of connection pins positioned side by side (e.g. at one and the same side wall), the soldering connections of those connection pins will tear apart first that are positioned outermost at the housing (e.g. positioned most right or most left at the front or rear side wall)—the tensions produced by the above-mentioned different coefficients of expansion of the circuit board and the semiconductor device housing are greatest with these pins.
The breaking up or tearing apart of soldering connections is one of the most frequent reasons for the failure of semiconductor device modules.